I think he meant the light for now, for light acclimation or something? Idk, but I would move it to your tank op, the one that i presume is already fully cycled(6+ months)I will agree with you on the light and six months, but disagree with you on an inexperienced person adding hammer or any hard coral in a three week old build.
I just setup a new tank, i waited a week to get a fish(I do fish in cycles) and another 3-4 weeks to get a goby. I would wait more time for s coral, first should be a zoa or a shroom or something, just so he can get used to reefing if he’s new